It is known to combine the outputs of a number of devices, such as high power amplifiers. This can be advantageous as it may deliver a method of obtaining higher output powers than might otherwise conveniently be obtainable, for example in a radio base station, or it may enable efficiencies of amplifiers to be increased by running a plurality of amplifiers of different power outputs in combination in order to achieve a desired power output. There may also be other instances in which it is desirable to combine the outputs of electronic devices.
Combiners are known. For example a Wilkinson Combiner System will work acceptably to combine the outputs of a plurality of amplifiers provided that all of the amplifiers are operating. However, should one amplifier fail, then the loss of output power is many times greater than the original contribution of that amplifier. This is due to the fact that not only is the contribution from that amplifier lost, but the amplifier can now become a load and the power from the other amplifiers is now wasted as it flows through the output impedance of the amplifier plus the balancing loads present as part of the combiner. The balancing loads therefore need to be adequately rated to cope with the possibility of amplifier failure and hence can become very large, possibly needing to be rated at several hundred watts in some cases.